Messages in this thread Patch in this message | | | From | Yajun Deng <> | Subject | [PATCH v4] sched/rt: fix the case where sched_rt_period_us is negative | Date | Tue, 17 May 2022 14:29:18 +0800 |
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The proc_dointvec() is for integer, but sysctl_sched_rt_period is a unsigned integer, proc_dointvec() would convert negative number into positive number. So both proc_dointvec() and sched_rt_global_validate() aren't return error even if we set a negative number.
Use proc_dointvec_minmax() instead of proc_dointvec() and use extra1 limit the minimum value for sched_rt_period_us/sched_rt_runtime_us.
Make sysctl_sched_rt_period integer to match proc_dointvec_minmax().
v4: - Make sysctl_sched_rt_period integer (Valentin Schneider) v2: - Remove sched_rr_timeslice_ms related changes (Valentin Schneider)
Fixes: d0b27fa77854 ("sched: rt-group: synchonised bandwidth period") Signed-off-by: Yajun Deng <yajun.deng@linux.dev> --- kernel/sched/rt.c | 11 +++++------ kernel/sched/sched.h | 2 +- 2 files changed, 6 insertions(+), 7 deletions(-)
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 8c9ed9664840..cafc580edbe4 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -16,7 +16,7 @@ struct rt_bandwidth def_rt_bandwidth; * period over which we measure -rt task CPU usage in us. * default: 1s */ -unsigned int sysctl_sched_rt_period = 1000000; +int sysctl_sched_rt_period = 1000000; /* * part of the period that we allow rt tasks to run in us. @@ -34,9 +34,10 @@ static struct ctl_table sched_rt_sysctls[] = { { .procname = "sched_rt_period_us", .data = &sysctl_sched_rt_period, - .maxlen = sizeof(unsigned int), + .maxlen = sizeof(int), .mode = 0644, .proc_handler = sched_rt_handler, + .extra1 = SYSCTL_ONE, }, { .procname = "sched_rt_runtime_us", @@ -44,6 +45,7 @@ static struct ctl_table sched_rt_sysctls[] = { .maxlen = sizeof(int), .mode = 0644, .proc_handler = sched_rt_handler, + .extra1 = SYSCTL_NEG_ONE, }, { .procname = "sched_rr_timeslice_ms", @@ -2960,9 +2962,6 @@ static int sched_rt_global_constraints(void) #ifdef CONFIG_SYSCTL static int sched_rt_global_validate(void) { - if (sysctl_sched_rt_period <= 0) - return -EINVAL; - if ((sysctl_sched_rt_runtime != RUNTIME_INF) && ((sysctl_sched_rt_runtime > sysctl_sched_rt_period) || ((u64)sysctl_sched_rt_runtime * @@ -2993,7 +2992,7 @@ static int sched_rt_handler(struct ctl_table *table, int write, void *buffer, old_period = sysctl_sched_rt_period; old_runtime = sysctl_sched_rt_runtime; - ret = proc_dointvec(table, write, buffer, lenp, ppos); + ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); if (!ret && write) { ret = sched_rt_global_validate(); diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 1f97f357aacd..1cb4d47b3e47 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -115,7 +115,7 @@ extern long calc_load_fold_active(struct rq *this_rq, long adjust); extern void call_trace_sched_update_nr_running(struct rq *rq, int count); -extern unsigned int sysctl_sched_rt_period; +extern int sysctl_sched_rt_period; extern int sysctl_sched_rt_runtime; extern int sched_rr_timeslice; -- 2.25.1
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